Sewing machines



Dec. 11, 1956 M. BLUMENKRANTZ SEWING MACHINES 6 Sheets-Sheet 1 Filed Jan. 9, 1956 A T TOR/VE Y Dec. 1l, 1956 M. BLUMENKRANTZ SEWING MACHINES Filed Jan. 9, 1956 INVENTOR. MAX BLUMENKRANTZ BY Ua l ATTQRNE 'Y Dec. 11, 1956 M. BLUMENKRANTZ SEWING MACHINES 6 Sheets-Sheet 3 Filed Jan. 9, 1956 AT TORNEY Dec. 11, 1956 M. BLUMENKRANTZ SEWING MACHINES 6 Sheets-Sheet 4 Filed Jan. 9, 1956 INVENToR. MAX BLUHENKRANTZ AT TORIYE Y Dec. 11, 1956 M. BLUMENKRANTZ 2,773,266

SEWING MACHINES Filed Jan. 9, 1956 6 Sheets-Sheet 5 AT TORNE Y DeC- 11, 1956 M. BLuMr-:NKRANTZ 2,773,266

SEWING MACHINES Filed Jan. 9, 1956 6 Sheets-Sheet 6 INVENTOR.

'MAX BLUMENKRANTZ BY An-ivf United States Patent SEWING MACHINES Max Blumenkrantz, New York, 2

Application January 9, 1956, Serial No. 558,149

2 Ciaimrs. (Cl. 2--278) This invention relates to sewing machines and has for an object the provision of novel mechanism for causing the machine to cease stitching, at the will of the operator, while continuing to feed the work forward, thereby leaving spaces or gaps in the stitching, thereby eliminating the placing of stitches in unwanted places in the sewing, and the necessity of removing them afterwards.

Another object of the invention is the provision, in a sewing machine, of means to roll the edges of a fabric strip about cords or the like and feed them to a pair of spaced apart needles, means to feed said strip to said needles and means under control of an operator for association or disassociating stitch forming elements with said needles and thereby causing stitches to be formed in said strip only where they are wanted, thus eliminating the necessity of ripping out stitches, as has been the case heretofore.

Other objects and advantages of the invention will be apparent to those skilled in the art, upon a study of this specification and the accompanying drawings.

Referring to the drawings which are given by way of example to illustrate the invention:

Figure l is a side elevation of a sewing machine made according to the invention;

Figure 2 is a view of a longitudinal portion of a welted boxing, which is shown as an example of one of the many operations performed by the machine;

Figure 3 is a sectional View taken along the line 3-3 of Figure 2;

Figure 4 is a perspective View of one of my improved welt forming devices;

Figure 5 is a view taken along the line 5 5 of Figure 4;

Figure 6 is a perspective view of a modified form of welt forming device;

Figure 7 is a sectional elevation taken along the line 7-7 of Figure 6;

Figure 8 is a perspective view of the cooperating ele` v ments of my machine for stitching double seams and also showing a simple arrangement for displacing the looper bar in the machine for causing it to cease stitching whenever any operations indicate that unstitched gaps shall 'be left in the work to avoid having to rip stitches out;

Figure 9 shows a loopei' support that has been displaced to a position where the loopers cannot cooperate with the needles, and consequently no stitches are made;

Figure 10 is a view taken near the right end of Figure y 8, looking toward the left;

Figure 11 is a perspective view of an eccentric shaft employed for displacing the looper support; v

Figure 12 is an elevation, partly in section, taken along the line 12-12 of Figure 8;

Figure 13 is an elevation, partly in section, taken along the line 13-13 of Figure 10;

Figure 14 is an elevation of a needle bar adapted to hold a pair of needles in a plurality of spaced apart relations by merely changing the needles into different sets of holes in accordance with the desired distance between Patented Dec. lli, 1F56 2 welts and showing its relationship to the presser foot; and the relationship of the loopers to the needles, the loopers being just as easy to change for different spacings as the needles are;

Figure 15 is a fragmentary cross-sectional view taken along the line 15-15 of Figure 14;

Figure 16 is an elevation, partly in section, taken along the line lr6-16 of Figure 14 showing the relationship of the needle to the presser foot and the needle plate of the machine;

Figure 17 Ais a perspective view of a modified form of folder devised to form double welt boxings and the like;

Figure 18 is a view of the folder as seen on the line 118-18 of Figure 17;

Figure 19 is a cross-sectional elevation taken on the line 19-19 of Figure 17, showing a fabric strip being folded around the cords;

Figure 20 is a view showing the double welt boxing as it comes from the folder ready to be delivered to stitching means in the machine;

Figure 21 is a view showing the boxing after it has been stitched in the machine;

Figure 22 is a sectional view taken along the yline 22--22 of Figure 21;

Figure 23 is a cross-sectional view of one of the welts having a cover or the like stitched thereto; and

Figure 24 is a sectional elevation of a portion of a cushion showing how the cover is folded over the stitches to produce a cushion with invisible or concealed stitches throughout` Referring rst to Figures 1, 2, S and 12, a main frame 20 has a front frame portion 2l, and spaced apart therefrom is a frame portion 22p. A hole 23 is formed in the portion 21, and a second hole 24 in alignment therewith is formed in the portion 22g. Mounted in these holes are bushings 25 and 26, respectively.

A shaft 27 has a portion 28 on one end thereof, and a second portion 29 on the other end thereof smaller in diameter and concentric therewith. Between these portions is an eccentric portion 30. Mounted on the portion 30 is a rocking dog" 39, which has a tubular portion with a bushing 41 in one end thereof, and a bushing 42 in the other end.

Between the end of the dog 39; carrying the bushing 41 and the adjacent end of the bushing 25', is a washer 34, and between the other end of the dog 39 and the bushing 26 is a washer 31. In assembling the shaft V27, the dog 39 and the washers 31 and 34 are positioned between the bushings 26 and 25, respectively, and then the shaft 27 is 'pushed endwise (small end 29 lirst from the front of the machine, as seen in Figure 8, or toward the right as seen in Figure l2) through the bushing 25 and the washer 34 and `into the bushings 41 and 42 of the dog 39, and thence through the washer 31 and into the bushing 26. When this operation is complete, the concentric portions 28 and 29 of the shaft 27 are journaled in the bushings `25 and 26 and the dog 39 is journaled on the eccentric `portion 30 of the shaft.

The shaft is secured in the relation described, by means of a washer 32 bearing against the right end of the bushing 26, and is secured to the end of the shaft portion 29 by means of a screw 33 engaging corresponding screw threads in an axial hole 38. Then a washer 35 is placed on the shaft portion 28, which protrudes from the bearing bushing 25, in contact with the outer end of the latter, as seen in Figure 8 or Figure 12.

The frame portion 21 has secured thereon, in spaced apart relation to the shaft 27, a limit plate 54 having upper and lower stops 55 and 56, respectively. The limit plate may be secured thereon in any desired manner, as by means of screws 47 passing through clearance holes in the plate and engaging threaded holes formed in the frame portion 21.

Mounted on the extending shaft portion 28 and in working contact with the washer 35 is the hub 36 of a lever 37 which extends between the stops 55 and 56. This lever has a lug 59 thereon with a hole therein permitting the attachment of a hook-shaped end 48 of a puller cable or chain 49 thereto.

The hub 36 has a lug 50 with a hole near its extremity vwhich is engaged by one end of a spring 51, and the other end of this spring is secured to the head of a screw member 53, which engages a threaded hole formed in the limit plate 54 which is offset in a notch 52 in said plate, thus the tension of the spring may be varied and the spring urges the lever 37 toward the stop 55 at all times.

The boss 36 is split so as to provide clamping lugs 43 and 44 with aligned holes formed therein to accommodate a clamping screw 45. As seen in Figure 8, the hole (not shown) in the lug 43 is a clearance hole for the screw, and the hole (not shown) in the lug 44 is threaded to accommodate the threads of the screw. In timing the loopers (as will be presently described) a lock nut 46 is loosened 'and then the screw is loosened and thereby the desired relative adjustment between the lever 37 and the shaft 27 may be effected, following which the screw and the nut .are tightened to retain such adjustment.

The rocking dog 39 has, preferably formed integral therewith, an arm or lever 60 which is normally disposed substantially vertically, and carries near its upper end yscrew means 61 which functions as a crank pin.

A depending crank member support 63 has spaced apart .arcuate slots 64 and 65 formed therein, and a bearing stud 66 is adjustably secured in the slot 64 and it has a portion 67 larger in diameter than the stud comprising a shoulder against which the hub 68 of a crank member 69 bears. The hub 68 has a bearing therein (not shown) which is journaled on the stud 66. Threadedly engaging ,the stud 66, forwardly of the bearing surface is a disc member 70 provided with threaded radial holes 71 to accommodate set screws. An axially disposed screw 72 carries a lock nut 73 and functions to retain the disc tapped hole 74 therein, and threadedly engaging said tapped hole is a shouldered screw 7S. Preferably formed integral with the depending support, Figure 8, is a shaft vportion 120 which is journaled in the bearing boss 62 on one end and is journaled in a bearing 119 in the frame portion 121, and this shaft portion carries washers such as the one shown at 122 to eliminate end play of the shaft portion 120.

. The shaft portion has a clamping boss 123 which is clamped thereon by means of a screw 124. Extending from the boss 123 is an arm 125 which is pivotedly connected to a bifurcated portion 126 of a dog 127 by means of a pivot pin (not shown). The dog 127 has a portion which embraces an eccentric 128 carried on the main shaft 85. A looper supporting bar 76 has a pair of spaced apart threaded holes (not shown) therein, and these holes are engaged by shouldered screws 77 which extend through bearing holes formed in the upper ends of the crank members 69.

A bearing member 78, comprised of separate portions 79 and 80 which are secured together by means of screws 110 and lock nuts 111, and which between themselves form a bearing in which the screw means 61 is journaled. The portion 79 has a threaded axial hole therein, and this is adjustably engaged by one end of a threaded` rod 82 which carries a lock nut 83. On its other end, the threaded rod 82 engages a corresponding threaded hole 4 in the bearing elements, and this rod may be adjusted by loosening the lock nuts 83 and 84, and by having right hand threads on one end of the rod 82 and in one of the bearing member ends, and by having left hand threads on the other end of the rod and in the other bearing member end, then, with the lock nuts 83, 84 loose, the bearing elements 78 and 78a may be adjusted toward or away from one another by turning the rod 82 in one direction or the other. When the desired adjustment is obtained the lock nuts are again tightened.

The screws 77 engage corresponding spaced apart threaded holes 81 formed in the looper support bar 76, and thus the crank members 69 are moved in unison by the arm 60 as the rocking dog 39 is moved.

The rocking dog 39 may be moved substantially by pulling the lever 37 from a position closely adjacent to the stop 5S, to a position adjacent to the other stop 56. This is done by an operator depressing a pedal (not shown) which in turn pulls the lever 37 down by means of a cable 49, as will hereinafter be explained.

The other motion of the rocking dog is effected by the main shaft. Referring to Figures l0 and 13, the main shaft 85 may be journaled in a bearing 86 formed in a frame member 87. Carried on the shaft 85 is an eccentric movement 88, which is embraced by the two halves 89 and 90 of a connecting rod 91. These halves are secured in embracing relation with the eccentric by means of screws 92.

The other end of the connecting rod 91 has a pair of halves similar in some respects to the halves 89 and 90. These halves are designated as 93 and 94, which are secured together by screws 95. The half 93 is formed integral with the connecting rod body 91, and within said halves, a spheroidal socket 96 is formed, which cooperates with a ball 97 carried on a second arm 98 on the rocking dog 39, so that the eccentric and the connecting rod effect the rocking of 39 and the oscillation of the looper support bar 76.

Detachably mounted in spaced apart relation on the looper support 76 are loopers 99 each having a downwardly extending shank (not shown) which extends into a vertical hole in the support bar 76, and is secured therein by means of a set screw 100, and these loopers normally cooperate with needles 101, which are secured in sockets formed in a needle bar 102 by means of screws 103.

The needle bar is secured on a vertical reciprocating shaft 104 which is moved by mechanism within the head 105 which moves in a definite time relation with the normal movement of said loopers and normally each time the needle with its thread makes a movement down and up again, the cooperative looper with its thread, cooperates to produce a stitch and they continue to form stitches until something happens to upset the cooperation.

The loopers must be oscillated on an oval path while cooperating with the needles to produce stitches. The eccentric 128 on the main shaft 85, through the mecha ynism described, causes the bifurcated portion 126 and the arm to oscillate the shaft portion 120 with the result that the depending portion 63 thereof carrying the crank members 69 is rocked about the axis of the shaft portion 120, thereby shifting the loopers 99 from positions close to the rear of the needles 101 to positions close to the needels in front-thus continuing as long as the machine is operating normally.

At the same time, the loopers are moved from right to left repetitively, and the combination of these two movements result in the needle and the looper. in each instance, cooperating to form a stitch.

The action of the looper is as follows: it moves from right to left in back of the needle (as one is facing the machine from the front) as the needle rises.l The needle moves back down, and at the same time the looper moves to the right and passes the needle in front. This latter movement is termed the avoiding motion of the looper in respect to the needle. The above action is repeated to form each stitch.

Upsetting the cooperation is effected by depressing a pedal (not shown) to which the cable 49 is attached, and thereby swinging the lever 37 down to a` point where it contacts the stop 56. This causes the shaft 27 to partially rotate, and the eccentric portion 30 of this shaft is caused to rotate partially to a point where the rocking dog 39 cannot rock sufficiently to bring the loopers into cooperative relation with the needles.

This means that as long as the lever 37 is in contact with` the surface of the lower stop 56 no stitching is effected, and as long as the lever is in contact with the stop 55 stitches are formed, due to the cooperation of the needles with the loopers.

A needle plate 106 is secured on a needle plate support 107 by means of screws 10S, and the support is in turn secured on a work surface (not shown for the sake of clarity) by means of screws 19.

The needle plate 1116 has spaced apart clearance holes 129 through which the needles 101 operate. This plate also has a series of slots 130 through which the serrated faces 13 1 of the feed dogs 132 operate. These are ope erated by mechanism, which will be presently described, and are timed to feed the work forwardly after the needles have left the work moving upwardly and before the needles again move downwardly to engage the Work again. Where a puller is employed, the feeding is effected conjointly by the feeding dogs and the puller, as will also be presently described.

In Figure 8, the presser foot, and the mechanism for raising and lowering it, are omitted for the sake of clarity. The presser foot is shown in Figure l however, Where the presser foot 112 has a tubular shank portion 113, the interior bore cf which lits on a vertical presser foot shaft 1-15 ,and is secured thereonby means of a set screw 114. The presser foot has an inclined portion 116 with a slanting face 117. Formed in the presser foot 112 beginning in the face 117 and extending inwardly in the direction of movement of the work are spaced apart grooves one of which is shown at 118. These grooves are provided to accommodate the cords and the fabric folded about said cords, as will presently be described.

Referring now to Figure l, the main shaft has an undercut beveled groove (not shown) in the end thereof, and a T bolt 135 has its head engaging said beveled groove. Mounted on the shank of the T bolt 135 is a bushing 135g upon which a dog 141 is mounted. The dog 141 has a split boss formed of lugs 137 and 137:1. The lug 137 has a clearance hole for the shank of the screw 138 and the lug 137a has a threaded hole which 1s engaged by the screw, and by means of the screw, all lost motion may be taken out by means of the screw, and the lock nut thereon is provided for retaining the adjust ment.

The T bolt has a cross-threaded hole therein engaged by the screw 136, by means of which the length of stitches may be set. A nut 161i threadedly engages the shank of the T bolt 135, and clamps and locks the disc 133, the T bolt and the shaft 35 together. The locking nut 160 must be loosened before any setting involving the length of the stitches is attempted, and after loosening said nut, the adjustments may then be made and the locking nut 16d is again tightened to retain such adjustment. The disc 133 has a cut-off or flattened portion that carries a plate member 139, which is secured thereto by means of screws 140, and said plate member supports the screw 13e.

' The dog 141 has a hole therein which carries wicking 4142, that cooperates with other oil wicking, which will presently be described.

The dog 141 has journaied in a hole in the end (oppo site the end 142) a stud 143 which is fixed on one end of aconnecting rod 145 by means of a set screw 144. The other end of the connecting rod carries a split boss 146 with a splitv lug portion 149 with aligned holes` there.- through one of which isa clear-ance hole and theother of which is threaded. A clamping screw 150 extends through the clearance hole and engages the threaded hole. The boss 146 has a hole therein which its over and is clamped to a iixed stud 147 carried by a lever 148 which is in turn journaled on a shaft 151 carried by a frame member 152.

The Upper end 153 of the lever 148 is bifurcated and carries a shaft element 154 upon which the left end portion 15S of the feed dog bracket 132 is pivoted. Beneath the feed dog bracket 132 which supports the feed dogs 131 is a cam or eccentric 156 which is not visible in Figure 1 but which may be seen in Figure 8, however part of the feed dog is broken away for the sake of clarity. The eccentric 156 raises and lowers the feed dog 1,32` once during each revolution of the main shaft 85. At the same time the rotation of said shaft rotates the dog 141 (in accordance with the setting for stitch length), and the connecting rod 145 gives the lever 148 a back and forth movement and this is imparted to the feed dogs 131 due to the connection of the left end of the feed dog bracket to the lever 148, consequently the feed dogs move the work forward, moves downwardly out of contact with the work, then moves back to its initial position and then upwardly in contact with the work ready to advance the Work to a point where the next stitch is to be made.`

Guards are provided for the needles, and one such guard is shown in Figure 8 and designated by the numeral 205. They are carried on the feed dog bracket 132 `and secured thereon by means of screws 206. These guards one for each needle) normally rest lightly against the back of the needles 101, and prevent the needles from glancing off the loopers when sewing over-seams etc., they also prevent the skipping of stitches, and needle breakage.

A hollow tube 115,7 extends through a cross-wall 153 and extends horizontally as shown in Figure 1, and has a cutaway portion 159 which exposes a portion of an oiling wick 173 so that as the machine is operated the wick is wiped by the dog 141, thereby insuring proper oiling at all times during said operation of the dog and `associated elements.

To abet the feeding of the work, the nature of which will be presently described, a puller is employed.

The puller is weil known in the art, and of itself forms no part of my invention, and only such parts of the puller are shown yas necessary to give a clear idea of how the puller operates. A frame 161 has a sub-base 162 163, and `a leveling arrangement including screws, one of which is shown at 164, for making the upper surface of the main puller roller 165 substantially level with the upper surface of the support plate 107.

The puller roller 165 is provided with rows of sernations 166 which engage the work and abet feeding when a pressure roller 168 exerts a downward pressure upon the work 175. The pressure roller has a shaft 169` which extends into aligned bearings formed in the legs of a yoke member 170. A shaft 171 has an enlarged portion 172 which is urged downwardly by springs (not shown). The puller roller 165 has ya shaft 167 which is connected to mechanism (not shown) controlled by and operated in time relation with the machine mechanism, and adjusted so that the pull exerted by the puller is only slightly different from that of the feed of the machine. As an example, if the machine alone sews 9 stitches per inch, it should sew 8 stitches per inch with. the puller engaged. The work 175 in the example given is termed welted boxing, side boxing or cushion boxing, and is comprised ofa fabric web 174 which is folded about welt cords 176 and 177 in a special folder and double stitched by the machine to form the welts on both edges during a single pass through the machine. In carrying on such operations it has heretofore been necessary to rip out stitches at certain intervals, but with the machine described herein, the depression of Va pedal (not shown) effects the movement of the lever 37, Fig. 8, and the partial rotation of the eccentric shaft 27, and thereby prevents the loopers 99 from cooperating with the needles and forming stitches. This is under control of the operator and on such welted boxings the stitches, that would have had to be ripped out, are prevented from forming. A second support plate 178 has one end secured to the support plate 107, and carries a socket to body 179 with a hole therein which is in alignment with a like hole in a bracket member 180 secured on the main base 20 in any suitable manner, as by screws 181. Mounted in said aligned holes is a guy or bracing rod 182 for rigidly supporting the outer end of a plate 178. A folder 185 shown in Figs. 6 and 7 has brackets 183 with screw holes 184 therein to be employed in mounting the folder on a support, as will be hereinafter explained. The folder 185 has an outer casing 186 which is tapered, and which 4has a strengthening bead 187 about its larger end, and which has an elongated slot 188 extending from the bead to a point spaced apart from the small end 189.

Adjacent to the end having the bead 187 on opposite sides of the outer casing are the brackets 183 above referred to. As shown in Fig. 7, the outer casing 186 has extremities 190 and 191 terminating on lines spaced apart from each other. The folder has an inner member 192 which forms an inner guide, and within the space between the inner member 192 and the outer c-asing a plate portion 193 extends inwardly from the end 189 and joins the portion 192. On each edge of the plate portion 193 are arcuate cord guides 194 and 195 for providing accurate guidance for the cords 176 and 177.

Between the plate portion 193 and the extremities 190 and 191 are elongated laterally disposed U-shaped channels 196 and 197. Preferably formed integral with the channel 196 is a support member 198 having a slot 199 therein. Secured midway of the plate portion 193 is a strip 200 which carries threaded holes to accommodate clamping screws 201 which pass through the clearance hole or slot 199 Iand enables an operator to adjust the channel relative to the lower extremity 202 of the web 174.

The other channel 197 has preferably formed integral therewith a support member 204, like the one shown at- 198 and adjustably secured in the same manner as the one shown at 198, a locking screw like the screw 201 being employed to retain the channel in the proper relation to guide the inner extremity 203 of the web 174.v Y

This means that the channels may be adjusted for any desired width of the extremities 202 and 203.

Referring again to Figure l, the folder 185 above described is mounted on the support of plate 178 with the end 189 adjacent to the edge 117 of the presser foot 112 and with the holes 184 in the brackets 183 aligned with corresponding threaded holes formed in the support plate 178. Screws, one of which is shown at 207 are employed to rigidly secure the folder in the proper position on the support plate 178.

Referring now to Figures 4 and 5, I show a modified form of folder wherein the elements which are substantially identical with corresponding ones described in connection with Figures 6 and 7 are designated by the same numerals used in the latter figures, followed by the letter a or b.

The modified folder 210 has mounting brackets 183m with holes 184 therein. This folder has an outer casing 208 which is tapered and which has a stiffening bead 18701 about its larger end, and which has an elongated slot 18811 in s-aid outer casing and a continuation slot 188b in a hinged top plate 209. This top plate-has its extremities in the form of rolls, one of which is shown yat 213, embracing a rod or shaft 214 which is journaled ..8 in spaced apart 'blocks 215 whichv are mounted on the' member 208.

Secured to the casing 208 is an offset spring 217, and cooperating therewith is a lever 128 which has one end 219 thereof soldered to the hinged top plate 209, and the other end 220 is free to be depressed for raising the top plate about its hinge shaft 214.

Secured on the side of the outer casing near the small end is a reinforcing plate 221. A curved plate 222 is secured to a straight portion 223 of an arm 224. This arm is curved and it has a screw 225 securing it to the plate 221. A screw 226 engages a threaded hole in the arrn 224 and forms a settable limit for the distance between the curved plate 222 and the curved face 194e, and such setting may be retained by means of the locknut. A threaded screw 229 is screwed into the plate 221 and extends through a clearance hole in the arm 224. A spring 227 embraces the body of 229, and a thumb nut 228 is for adjusting the arm 224 so that it exerts a pre-determined or wanted urge upon said arm and the curved plate 222 carried thereby.

The operator then raises the presser foot and grasps the two fabric embraced cords and pulls them forward and raises the presser roller 168 and places the web and cords between the roller 168 and the puller roller 165. Then the machine is ready to operate.

In the modification yshown in Figure 14, the needle bar 102a carries pairs of sockets on each side so that the needles may be placed in the outer sockets when it is desired to form a wider welt or they may be placed in the inner sockets when the welt to be sewn is not so wide.

Now with the needles in the inner sockets (shown in solid lines) the presser foot 116a which has the grooves 112:1 and 112b is in the proper position to accommodate the fabric embraced cords, while if the needles are positioned in the outer sockets (the ones shown in dot-dash lines) a wider presser foot is substituted having grooves 112m and 112bb to accommodate the cords.

Now when the needles are used in the inner sockets the loopers 99a are positioned in the inner sockets and secured by screws 10061 and b and will cooperate with the needles (as shown in solid lines) in Figure 14.

Where the welt is wider, the needles would be positioned in the sockets as shown in dot-dash lines and the loopers would be positioned in the outer holes in the support 76a and would be secured therein by screws 100bb and 100ml.

Operation With both forms of the folder above described, the cords are pushed through the passages via the guides (such as guides 230 and 231) and they exit from the folders engaged by the guides 194 and 195 of the form of folder shown in Figure 6. In the form of folder shown in Figure 4, the cords exit from the folder between the guide 194a and its cooperative curved plate 222, on one side -and between the guide a and the curved plate 222a on the other side.

These cords are pulled forward, with the presser foot 112 raised and when they are far enough forward to be engaged by the presser foot, the latter is let down, the operator making sure that the cords lie in the grooves 112a land 112b, Figure 14V Then the fabric strip 174 is fed into the folder by placing it upon the inner member 192, centralizing it in a lateral sense and then pushing it forwardly (toward the small end 193 of the folder) using the finger in the slot 188 (or the slot 188:1, 188b) to facilitate the operation, thereby causing the fabric web to emerge from the folder yin embracing rel-ation with the two cords. As the machine is operated, the cords are advanced, so that the fabric embraced cords pass under the presser foot, and the fabric strip 174 is stitched to retain it in said embracing relation.

When the stitching has advanced to a predetermined point and it is desired to prevent stitches from forming in a predetermined length of theweb (to avoid having to rip out such stitches later) the operator presses a foot pedal or .throws a lever, either one of which causes the eccentric shaft 27 to rotate through a predetermined number of degrees, thereby upsetting the cooperative relation of the needles and the loopers and preventing the formation of stitches where stitches are not wanted, for said predetermined length.

In the modification shown in Figure 14, the needle bar 102:1 carries pairs of sockets on each side so that the needles may be placed in the outer sockets when it is desired to form a wider Welt or they may be placed in the inner sockets when the welt to be sewn is not so wide.

Now with the needles in the inner sockets (shown in solid lines) the presser foot 116ey which has the grooves 112e and 112b is in the proper position to accommodate the fabric embraced cords, while if the needles are positioned in the outer sockets (the ones shown in dot-dash lines) a Wider presser foot; is,` substituted having grooves 112ml and 11,2,bvb to `accommodate the cords.

Now when the needles are used in the inner sockets the loopers 99a are positioned in the inner sockets and secured by screws 100a and ltltlb and will cooperate with the needles (as shown in solid lines) in Figure 14.

Where the welt is wider, the needles would be positioned in the sockets as shown in dot-dash lines and the loopersl would be positioned in the outer holes in the support 76a and Would-be secured therein by screws 100M: and 100m.

Referring now to Figure 15, a section is taken along the line 15-15 of Figure 14 to show the arrangement of the needle clamping screws 1035 land 103bb and also to show a thread guiding plate 232 which is secured on the needle clamp by means of a central screw 233, and this plate has a thread hole 234 for supplying thread to the needle in the inner position while a thread hole 235 therein supplies thread to the needles in the outer dot-dash positions.

On the opposite side of the needle clamp 102 is positioned a second identical thread carrying plate 232, so the description of it need not be repeated.

Figure 16 shows from the right side along the section line to the left of the presser foot shaft the relation between the needle 101, the presser foot 112, the needle plate 106 and the support plate 107. From this figure, it will be noted that the presser foot has a curved welt portion which accommodates the cord with its fabric embrasure, and within the presser foot so as to put stitches at just the right place, is a clearance hole 236 to match up with the needle clearance hole 129 formed in the needle plate 106. By this arrangement, I effectively 4apply the stitching as shown in Figures 2 and 3.

Referring now to Figures 17, 18, and 19, I show yet another modified form of folder for forming a double welt boxing or the like adapted to form cushions with concealed or invisible stitches. This folder is generally inverted as compared with the other two folders described above. This folder, generally designated by the numeral 230, has la main body 237 with sides 238 and 239 extendlng upwardly and forming a trough. Mounting brackets 240 and 241 are secured on the outside surfaces of the sides 238 and 239 and they carry mounting holes which, when screwed to the plate 178 of the machine by means of screws 207, the discharge end (to be presently described) is in the proper position to feed the Welts to the presser foot and the needles.

On the underside of the large end of the main body is a reinforcing bead 242. The side 238 tapers toward the discharge end, and it has slightly curved portion 243, where the side is depressed inwardly to accommodate a frustro-conical cord guide tube 247. This tube is soldered, brazed or otherwise positively secured on the side 238. It has a reinforcing bead 248 about the large end thereof, and it has a small end 249 adjacent to a curved cord guide plate 246. The guide 246 is secured on the I0 edge of a curved portionA 245 of the material of the side 238 beyond a notched portion 244, and the portion 245 is formed into a semi-circle to bring the remaining flat portion substantially parallel to the small end 250 of the main body 237.

The side 239 is also tapered towards the end 250 and it has a similar slightly curved portion (not shown) to accommodate a like frustro-conical cord guide tube 251, which is positively secured on the side 239. This tube has a reinforcing bead 252 about its larger end. The small end of `the tube 251 is positioned adjacent to a cord guide 254 in substantially the same manner as the small end 249 is described to be relative to the guide246. The portion 245 is formed into a semi-circle to bring the remaining iiat portion 253 substantially parallel to the small end 250 of the main body 237.

The folder has an inner body 231 which is generally U-shaped in section at the larger end. It has formed integral therewith substantially parallel sides 255 and 256, and the side portion 255 has an angular portion 257, while the side 256 hasl an angular portion 258. These angular portions rest upon the upper edges of the sides 238l and 239, and are secured thereto in certain zones, which will be presently described. The proportions of the sides and the angular portions are such that the space 259, between the surface of the main body 237 at the largeend', the space 260 between the sides 239 and 256', and the space 261 between the sides 238 and 255 are substantially equal` for the admittance of fabric web materialsinto the folder. The larger end of the inner body 231 may be provided with a bead or the like reinforcing strip 262.

The angular portion 257 rests upon and is positively secured to the upper edge of the side 238 by means of soldering, brazing or any other suitable means in a zone extending from a point 263 to the point where the curved portion 243 borders one edge of the notched portion 244 as is clearly shown in Figure i7. The `angular portion 258 rests upon and is secured to the upper edge of the side 239 in the same manner and within. a like zone as that in which the portion 257 is secured to the edge of 238 as just described.

A tongue portion 264 extends forwardly to the discharge end of the folder, and an eXtra folding plate 265 is secured on the tongue 264 in cooperative relation with the cord guide 246 as shown in Figure 19. This folding plate has a semicircular portion 267, and a straight portion 266 which is substantially parallel to the tongue 264, and the straight portion supporting the cord guide 246. It also has a laterally extending portion 268 which is soldered or otherwise positively secured to the surface of the tongue 264. The folding plate 265 overlaps and is also secured to the upper surface of the angular portion 258 in a zone extending from a point 269 to a point 270. The plate 265 has a substantial portion broken away so that the details above described may be clearly understood.

A second folding plate 271 is substantially identical Y with the folding plate 265 and is secured on the tongue 264 in cooperative relation with the cord guide 254. This folding plate has a semi-circular portion 272 and a straight portion 273 which is substantially parallel to the tongue 264, and the straight portion 253 supporting the cord guide 254. It also has a laterally extending portion 274 which is soldered or otherwise secured to the tongue 264 in a zone beginning at the point 289 and coextensive with the zone 269--270- An elongated slot 275 is formed in the inner body and having a central axis which is substantially central of said inner body to facilitate the pushing of the fabric strips through said folder.

It will be noted that from Figures 2, 3, and 7 that the folders of Figures 4 and 6 fold the edges of the fabric strip over the cords, and the strip is stitched between,

' 1l and yet adjacent to the two welts. However the stitching is visible.

The folder of Figures 17, 18, and 19 forms a similar fold 281 and 282 of the fabric web 276, (which is inverted) and then as the fabric web reaches the folding plates 265 and 271, extra folds 277 and 278 are formed about the cords 279 and 280, as seen in Figures 19 and 20.

Now, as seen in Figures 21 and 22, a row of stitching 283 is applied adjacent to but outside of the welt 277, and simultaneously with the formation of the row of stitches 283, a second row of stitches 284 is formed adjacent to but outside of the welt 278 at a single pass of the welt through the machine.

To form a cushion with invisible stitches, a cushion cover 285 is applied wrong side up by matching its border 286 with the border 278 (Figure 23) and securing them and the fold 278 together with a row of stitching 287. Following this the cushion cover is folded over; as shown in Figure 23 to position the right side uppermost in a horizontal sense and with the web 276 on the front, as shown. The other welt 279 with its folds 281 and 277 may have a bottom cover attached thereto in the same manner, and the cushion may have any desired kind of stuffing applied inside.

Although I have herein shown and described by way of example improvements in sewing machines of the type employing loopers for handling the bottom threads and modifications thereof including means to drop stitches at will and means to change welts from one width to another with a minimum of substitutions in the set-up,

I am not limited by the exact structure herein shown and described as many changes may be made in the arrangements shown and described within the` scope of the following claims:

-I claim:

1. As an article of manufacture, a double welted cushion boxing comprising a longitudinal strip of fabric material, the opposite edge portions of said longitudinal strip being folded about a pair of spaced apart substantially parallel cords and stitched to said longitudinal strip adjacent said cords, the said stitching being disposed inwardly from the edges to form attaching margins, said cords forming the longitudinal edges of said cushion boxing.

2. An article according to claim 1 wherein said attaching margins extend toward each other.

References Cited in the file of this patent UNITED STATES PATENTS 621,435 Struss Mar. 21, 1899 1,360,196 Delaney Nov. 23, 1920 1,387,639 Bolender et a1. Aug. 16, 1921 1,508,695 Hill Sept. 16, 1924 1,655,164 Schemmel Jan. 3, 1928 1,764,846 Maier June 17, 1930 1,877,001 McIlroy Sept. 13, 1932 2,108,061 Hale Feb. 15, 1938 2,439,332 Becker Apr. 6, 1948 2,688,293 Hayes et a1. Sept. 7, 1954 

